bcachefs: btree key cache pcpu freedlist

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Originally, the btree key cache code would always allocate new entries
by reusing from the recently-freed list, if that list wasn't empty. But
that behaviour was dropped, for lock contention reasons.

But it seems that entries stranded on the freed list have been
contributing to some of our oom issues, because long running btree
transactions will prevent them from being freed.

This patch re-adds allocating from the freed list, but it also adds
percpu buffers to solve the lock contention issues - and the new percpu
freed lists will improve the evict paths, too.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>

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Kent Overstreet 2022-06-17 01:07:54 -04:00 • committed by Kent Overstreet

parent 7bb61e8c0e

commit 8f7f566f57

2 changed files with 108 additions and 21 deletions

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121

fs/bcachefs/btree_key_cache.c

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8

fs/bcachefs/btree_types.h

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